3306, introduced in 1970s, to replace 1673 and 3160. Firstly widely used in CAT 225 excavator in 1973. Stopped in 1990 due to technology changed.
1987, Shanghai Diesel cooperate with Caterpillar to produce 3306 series engines. Shanghai Diesel brand is C series C6121. 1995-1997, Shanghai Diesel Engine(now is SNAT, belong to SAIC Motor- which used to be much smaller than Shanghai Diesel) stopped cooperation with Caterpillar.
2002 and 2006, Shanghai Diesel would like to re-cooperate with CAT but failed. Now SNAT still produce some CAT parts via the previous production line which just sell to oversea market.
C7 and C9 replaced 3306 around 2004.
Applications:
Original 3306 looks similar to 3406. 3306 with 2 valves, 3406 with 4 valves.
New 3306DI engines with 4 valves. Used in D6 and D7 Dozers, 12G, 14G and 140G Motorgraders.
In 1970s and 1980s, 3306 installed on all the major truck manufacturers Peterbuilt, Kenworth and Freightliner. vocational trucks, step vans, delivery vehicles and bread trucks.
CAT 3306B was a huge hit in the marine industry and was successfully installed in millions of small boats from tugs, dredges, ferries, pump boats, drifters, trawlers and fireboats.
Failures:
3306 is famous for reliability because of uncomplicated designs, while most notorious issues are: broken water pump shafts, failed or leaking front main oil seals, and dropped valves—although the latter scenario usually occurs after extremely high hours or miles have been accumulated.
